Interactive media (e.g., the Internet) has great potential for the targeting of advertisements (“ads”) to receptive audiences. One form of online advertising is ad syndication, which allows advertisers to extend their marketing reach by distributing ads to additional partners. For example, third party online publishers can place an advertiser's text or image ads on web properties with desirable content to drive online customers to the advertiser's website. An example of such a system is AdSense™ offered by Google, Inc.
A “conversion” occurs when a customer performs a certain action at the advertiser's website (e.g., registering, making a purchase, downloading content, providing information, clicking on a link). A conversion can be defined by the advertiser. Cost-Per-Action (CPA) for an advertiser is defined as the dollar cost for a conversion. Everything else being equal, an advertiser desires to have a low CPA for an ad. A click on a first ad displayed by a first publisher may have a higher chance of converting than a click on the same ad displayed by a second publisher. For example, an ad clicked on “Google.com” may have a higher probability of converting than the same ad clicked on a publisher network (e.g., the AdSense™ network). Thus, a click on an ad presented by a first publisher may be worth more than a click on the same ad presented by a second publisher. Therefore, ideally, the advertiser should bid less for the second publisher click than the first publisher click, and so the CPA paid by the advertiser would be the same for both publishers.